1. Field of the Invention
This invention relates to a lock device, and particularly to a lock with two layers of lock mechanism.
2. Description of the Prior Art
In a conventional cylindrical lock, the inner space of the casing is mounted with an upper tumbler seat and a lower tumbler seat; a plurality of symmetrical tumbler holes are furnished between the upper and lower tumbler seats to be loaded with tumblers and springs respectively; normally, the springs in the tumbler holes will push the front ends of the front tumblers to the positioning edge of the front end of the casing. Since the tumblers are different in length, they can mate with different keys for unlocking; after a correct key is plugged into the cylindrical lock, the unlock grooves on the front end of the cylindrical lock will push the front tumblers to move forwards to an interface between the upper tumbler seat and the lower tumbler seat, i.e., the front tumblers and the rear tumblers are put along a rotary tangent surface; then, a turning and driving plate of the cylindrical key will drive the upper tumbler seat to turn, and a transmission shaft of the upper tumbler seat will drive a driving arm to turn.
In a conventional lock device, the lock lamina or the lock tumblers mounted in a body casing are different in structure, and the key for unlocking the same is also different in structure; therefore, the lock-up function is also different. In the conventional laminated lock structure, the assembling procedures thereof is rather simple aside from the picklock factors; it can obtain a high manufacturing precision without being unlocked with a master key.
In the conventional locks, different locks are substantially different in the structure of their tumblers, i.e., each type of lock has its features; after a given period of being sold, the locking function thereof is subject to being learned or known by other person, and then it is subject to being unlocked easily.
The prime object of the present invention is to provide a lock device, in which a body casing is loaded with two different lock bodies, and the two lock bodies are connected together with a connection plate; the key of such a lock must be able to unlock the two different lock bodies simultaneously so as to drive the core bar in the lock to turn.
Another object of the present invention is to provide a lock device, in which the cylindrical hole is furnished with a key hole through the lower lock body; one end of the cylindrical hole and the body casing is furnished with a ring-shaped key groove for receiving a cylindrical key; the center of the cylindrical key has a flat key. During unlocking the lock, the flat key has to plug into the lower lock body, while the cylindrical key is plugged into the upper lock body so as to have the upper and lower tumblers and the lock lamina driven to the unlocking positions; then, the key can drive the core bar to turn.
Still another object of the present invention is to provide a lock device, in which the front part of the cylindrical hole is loaded with the upper lock body, while the rear part thereof is mounted with the lower lock body; the upper and lower lock bodies are connected together with a connection plate. The two lock bodies in the body casing should be unlocked with a key simultaneously so as to have the core bar to turn.
A further object of the present invention is to provide a lock device, in which the center of the connection plate is mounted on a movable member of the upper lock body; the outer edge of the connection plate is furnished with a limit groove and a guide groove for receiving one end of the bolt. After the key is plugged in to unlock the lock, the limit groove of the connection plate will connect with and limit the bolt to have the two lock bodies connected together so as to turn the core bar for unlocking.
A still further object of the present invention is to provide a lock device, in which the center of the lower lock body has a key hole, being smaller than that of the upper lock body so as to facilitate the key to plug in smoothly.
Yet another object of the present invention is to provide a lock device, in which the lower lock body is a laminated lock cylinder or the like, while the upper lock body is a cylinder-shaped lock core or the like.